The governors of western states and a Canadian province are partnering to combat climate change.

Governors of California, Oregon, Washington and the premier of British Columbia on Monday will announce the partnership at an event in San Francisco. Few specifics were available.

The deal stems from the Pacific Coast Collaborative, a group meant to organize climate change and clean energy policies. It links together economies with a combined GDP of $2.8 trillion, the fifth largest in the world, according to Brown’s office.